Imagens da página
PDF
ePub

use.

taking out at different intervals small | quantity of purple be added, the colour pieces of glass, arranged for the pur- will be perceivably benefited. pose, on which are laid similar colours RED.—1 part, terra de sienna ; 3, to those being fired. After the glass | enamel flux (2). The terra de sienna is burned it requires great precaution must be calcined over a slow fire until in cooling, for if suddenly cooled it its colour becomes of a dark red, after is apt to fly, consequently all sudden which wished several times in boiling changes of temperature should be water and ground with the flux for avoided.

RED ORANGE and YELLOW STAINS.— TRANSPARENT ORANGE.—1 part, ox12 parts, green vitriol calcined ; 1, ide of silver ; 10, enamel flux (2); 10, oxide of silver. The vitriol must be cal enamel flux (3); i, white enamel. cined to a reddish colour, and repeatedly YELLOW.-1 part, yellow, under glaze, washed with boiling water until it is | p. 46; 3, enamel flux (2); }, white completely freed from its acid, which enamel. will be known by the water being insipid | DARK BROWN.—1 part, highly calto the taste, then triturate the silver and cined copperas; 31, enamel flux (3). vitriol together in a mortar, after which RED BROWN.-1 part, black; 1, red; grind them up with spirits of tar for use. 1, enamel flux (4). Various temperatures in burning pro- LIGHT BROWN.—1 part, easy calcined duce various coloured stains, the highest | umber; 31, enamel flux (2). a red, a less an orange, and so on to a GREEN. — 1. 5 parts, cornelian red; yellow; but to procure a very deep red, 1, prepared purple. 2. 2 parts, blue ; the colour must be laid upon both sides 1, yellow. of the glass.

BLUE.-1. 8 parts, flint glass ; 3, redWHITE ENAMEL FOR PAINTING | lead ; 1, potash; 1, blue calx ; i, comGLASS. — 3 parts, borax calcined ; 2, mon salt. 2. 4 parts, borax; 43, fint flint; 1, oxide of tin; 1, Cornish stone. glass; 1, Aint; , potash ; ), prepared The basis of this enamel, which is in purple ; 1, blue calx. În preparing general opaque, may also be employed in these blues, let the materials be calcined assimilating the opaque natural stones. in an air furnace, and the whole mass These ingredients must be well mixed kept in a state of fusion for some time, up together, and fused in an air fur- a fine blue glass enamel will be produced ; nace in a crucible, the fire at first the cobalt blue calx should be of the applied very gradually, and the whole finest quality that possibly can be prorepeatedly stirred with an iron rod. / cured, and free from all impurities. The mixture by this calcination, and BLACK. — 1. 1 part, highly calcined by being kept for some time in fusion umber; 2, calcined borax; 1, red-lead; in an intense heat, acquires its fusibility 1, blue calx. 2. 1 part, manganese ; 1, aud opacity.

black fux. The best Turkey 'umber PURPLE. – 1. 20 parts, prepared should be procured for the first process, purple; 2), enamel flux (2); 1, white and calcined at the most intense heat that enamel. 2. 20 parts, prepared purple; can be produced in an air furnace, after 10, blue process; 51, enamel flux (2); which pound and mix up with the other 1, white enamel.

| materials; then calcine the whole toROSE COLOUR. — 20 parts, prepared gether in an air furnace, the degree of rose colour ; 1, white enamel. The heat will be sufficient when the whole purples and rose colours for glass paint mass is in fusion. ing are nearly the same mixtures as BLACK Flux, for glass staining.–15 those used for porcelain painting, with parts, red-lead ; 5, borax; 5, flint; 14 the addition of a small proportion of oxide of blue vitriol. flux and white enamel, the latter gives INDIGO BLUE.—1 part, precipitate of firmness to the colour ; in the course of gold; 41, enamel flux (4); À, white cnamel. working the rose colour, if a very small | These ingredier:s are simply ground

together for use. They produce a beau- | sponge ; there will remain only the tiful colour on glass, of'a fine purple hue. colour transferred to the glass, which This very expensive colour is adapted will be fixed by passing the glass through principally for painting the draperies of the ovens, figures, and is very susceptible of being Annealing Glass.—This consists injured by a high degree of heat. in puttiug the glass vessels, as soon as

ETCHING AND DEADENING COLOUR. they are furmed, and while they are yet 1. 7 parts, red-lead ; 2, calcined borax; hot, into a furnace or an oven, not so 2, Aint; i, oxide of tin. 2. 8 parts, hot as to re-melt them, and in which red-lead ; 6, flint glass ; 3, flint; }, they are suffered to cool gradually. It green copperas. The materials of the | is found to prevent their breaking easily, last two processes must be finely mixed particularly on exposure to heat. In and calcined in an air furnace, each pro- large works, annealing is performed by cess separately, after which take 2 parts passing the glass through the oven, by of No. 1 and 3 parts of No. 2, mix them means of revolving trays constructed for together, and repeat the calcination the purpose. again in an air furnace; then pound and Cutting Glass.-To cut glass vesgrind this frit for use, but be particular sels neatly, heat a rod of iron to redness, that it is ground very fine, for much and having filled the vessel the exact depends on the particles being minutely height you wish it to be cut with oil of mixed previous to using. The composi- | any kind, proceed very gradually to dip tion is afterwards laid on the glass with the red-hot iron into the oil, which, water, and a small quantity of refined heating all along the surface, the glass sugar dissolved in spring water applied suddenly chips and cracks right round, occasionally, the solution of sugar must when you can lift off the upper porbe of the consistence of thick oil; should tion clean by the surface of the oil. too large a quantity of the solution be If a tube is required to be cut, notch added, and by that means condensate it the tube at the point where it is to be too much, add a few drops of acetous divided with the edge of the file, or of a acid to the menstruum, it will imme | thin plate of hard steel, or with a diadiately regain a proper consistence, and mond ; after which press upon the two not at all injure the colour. When the | ends of the tube, as if to enlarge the deadening is laid on the glass, the figures notch, or what is better, give the tube a must be engraved or etched with a pointed slight smart blow. This method is sufinstrument made of wood, bone, or ivory, ficient for the breaking of small tubes. suitable to the subject, and afterwards Many persons habitually employ an burned in a kiln or muffle appropriated agate, or a common flint, which they for the purpose. It fires at a less tem hold in one hand, while with the other perature than stained glass, although they rub the tube over the sharp edge in some instances it will do in the same of the stone, taking the precaution of kiln.

securing the tube by the help of the To Transfer Engravings on |thumb. For tubes of great diameter, Glass.-Metallic colours prepared and employ a fine iron wire stretched in a mixed with fat oil, are applied to the bow, or, still better, the glass-cutter's stamp on the engraved brass or copper. | wheel; with either of these, assisted by · Wipe with the hand in the manner of the a mixture of emery and water, you can printers of coloured plates ; take a proof cut a circular trace round a large tube, on a sheet of silver paper, which is im- and then divide it with ease. When the mediately transferred on the tablet of portion which is to be removed from a the glass destined to be painted, being | tube is so small that you cannot easily careful to turn the coloured side against lay hold of it, cut a notch with a file, and the glass; it adheres to it, and so soon expose the notch to the point of a candlo es the copy is quite dry, take off the su- | Aame; the cut then flies round the tube, perfluous paper, by washing it with a | A good plan of cutting glass is to make use of a piece of iron heated to redness, moistened with pumice powder, and finish an angle or corner of which is to be on a cork wheel with putty and rottenapplied to the tube at the point where it stone. The engraver cuts in and roughs is to be cut, and then, if the fracture is the pattern with copper wheels, aided by uot at once effected by the action of the emery of various degrees of fineness, and hot iron, plunge suddenly into cold water. olive or sperm oil, and polishes the porAfter having made a notch with a file, tions intended with leaden disks and very or the edge of a flint, you introduce into | fine pumice powder and water. it a little water, and bring close upon it Painting Glass for the Magic the point of a wire, previously heated to Lantern.-Draw on paper the size of the melting point. This double appli- the glass the subject you mean to paint. cation of heat and moisture obliges the Fasten this at each end of the glass with notch to fly round the glass. Glaziers paste, or cement, to prevent it from slipuse for cutting glass a diamond splinter ping. Then reverse the glass so as to mounted in a holder.

have the paper underneath, and with To Draw on Glass.-Grind lamp some very black paint, mixed with varblack with gum-water and some com- | nish, draw with a fine camel-hair pencil mon salt; draw the design with a pen very lightly the outlines sketched on the or hair pencil ; or use a crayon made for paper which are reflected on the glass. the purpose.

It would add to the natural resemblanco Stencilling on Glass — Writ if the outlines were drawn with a strong ing on Glass.-Stencil plates may tint of each of the natural colours of the be cut out of thin sheets of metal or object; but in this respect the artist cardboard, in the same manner as ior | must please his fancy. When the outwall decoration, &c. If varnish colours lines are dry, colour and shade the are employed, lay them on as evenly as figures ; but observe to temper the possible, through the perforations in the colours with strong white varnish. plate, and harden afterwards in a stove i Pigments for Magic Lantern or oven. The metallic preparations used Slides.-The only pigments available in glass staining and painting are also l are the transparent and a few of the available, but require firing in a muffle, semi-transparent. The transparent inor a china painter's stove. Should the clude (beginning with the best for the process commonly cailed embossing be purpose) Prussian blue, gamboge, carwanted, paint the portions of glass left mine, verdigris, madder brown, indigo, uncovered by the spaces in the stencil | crimson lake, and ivory black. The plate with Brunswick black, dip or cover semi-transparent include raw sienna, with hydrofluoric acid, wash in clear / burnt sienna, cappah brown, and Vanwater and remove the black ground. dyke brown. No particular method of Every part that was covered will then mixing the colours is requisite. Ordinary present a polished even surface, the re oil or water colours will do, but they mainder will have been eaten into by the { must be ground extremely fine. The acid. If the raised parts are to have a pencils must be small and their points frosted appearance, rub them with a flat unexceptionable. Camel's-hair is preferpiece of marble moistened with fine emery able to sable for painting upon glass, its and water. For putting patterns or lines elasticity being less, and the trouble of on glass with a wheel, there are two working out the brush marks, which methods, one followed by glass cutters, must always be carefully attended to, the other by the engravers on glass, not so great. The best vehicle to use for The first-mentioned, rough in the pat thinning the colours is ordinary megilp, tern, with an iron mill supplied with a and not a drop more than is necessary trickling stream of sand and water, for properly working should be added, smooth out the rough marks on a wheel | for if the colours be made too thiu they of York or Warrington stone, polisa on | will run into each other and utterly a wooden wheel of willow or alder | ruin the painting. If water colonirs are

preferred, the best medium for laying or | is used, and they are chucked in a lathe. the first wash of colour is a hot solution Panes of glass should be laid on a soft bed of transparent gelatine. When this is of baize, or coarse linen. If the frosting dry and cold it admits of shading and is to be very fine, tinish with washed finishing without being disturbed, pro- emery and water. As a temporary frostvided the pencil be handled gently and ing for windows, mix together a strong, the medium be cold water. The oil hot solution of sui pate of magnesia and paintings require no varnishing, but the a clear solution of gum arabic, appiy transparency of the water colours is warm. Or use a strong solution of sulmuch' heightened by a thin coat of the phate of sodium warm, and when cool purest mastic varnish. In colouring the wash with gum-water to protect the sur pictures the quality of the light which face from being scratched. is to show them must be borne in mind. Drilling Glass. — Glass can be If it be the lime light, approximate as drilled with a common drill, but the nearly as possible to nature; but if it be safest method is to use a brooch drill. the light of an oil lamp, remember that No spear-pointed drill can be tempered its rays are greatly deficient in blue, the hard enough not to break. The brooch yellow proportionately preponderating, can either be used as a drill with a bow, and arrange the tints accordingly: for or by the hand. It should be selected of instance, the greens must be much bluer such a bore that it will make a hole of than natural, the yellows must incline the required size, at about one inch from to orange, and all shades of violet (the the end. It should be broken off sharp complementary of yellow) wholly es- | with a pair of pliers, at about an inch cnewed.

and a half, and when the sharp edges are Glass Cleaning.-Grease may be blunted by drilling, a fresh end should dissolved from glass by means of car- be made by breaking off an eighth of bonate soda, carbouate potass, or better an inch, and so on, until the hole is still, by caustic soda, made thus:-10 bored. It is always desirable to dril! parts of carbonate soda are dissolved in from both sides, as it prevents the glass 100 parts of water (10 oz. to 100 oz.), from breaking ; drill lightly, and lubriand heated to ebullition in a clean un- | cate with spirits of turpentine and oil of tinned iron vessel ; 8 parts of good quick- lavender, or a little camphor instead of lime are meanwhile slaked in a covered oil of lavender. Holes may be drilled basin, and the resulting hydrate of line through plate glass with a flat-ended added, little by little, to the boiling solu- copper drill and coarse emery and water. tion of carbonate, with frequent stirring. The end of the drill will gradually wear This will give a very strong caustic so- round, when it must be re-Aattened, or it lution, and should be used with care. will not hold the emery. Practically, Keep your hands out of the solution, and however, the best means of drilling holes dip the glass in by means of the pliers, in glass is by using a splinter of a diakeeping them moving while in the solu- mond. A brass drill is made to fit the tion. When the grease is dissolved or drill-stock, sawn down a little way with loosened, scrub with a brush, well rinse a notched knife to allow the splinter to in water, and dry.

fit tight, and the splinter fixed in the Frosting Glass.-Roll up tolera- split wire with hot shellac or sealingbly tightly a slip of tin, about 6 in. or wax. The drill is to be used quite 8 in. long and about 2 in. broad, or use a dry and with care. If the hole to be small flat piece of marble. Dip either drilled is wanted larger than the tool, of these in Croydon or glass-cutter's sand, drill a number of small holes close tomoistened with water; rub over the glass, gether to form a circle as large as the whether flat or round, dipping it fre- hole required, then join the holes with a quently in a pail or pan of clear water. small file. A splinter of diamond may This is the method employed for frosting be bought for 2s. (or -50) bi, enough to jugs, &c. For lamp glasses a wire brush | d:ill a in. holz.

Darkening Glass.-The follow-! be well secured by lead flushings, to ing, if neatly done, renders the glass prevent wet getting in, which might be obscure yet diaphanous :-Rub up, as for attended with serious consequences. In oil colours, a sufficient quantity of sugar the left-hand corner, against the back of lead with a little boiled linseed oil, wall, dig out a foundation and fix over a and distribute this uniformly over the furnace the set pot, used for boiling pane, from the end of a hog-hair tool by a dabbing, jerking motion, until the ap

FIG. 2. pearance of ground glass is obtained. It may be ornamented, when perfectly hard, by delineating the pattern with a stroug solution of caustic potash, giving it such time to act as experience dictates, and then expeditiously wiping out the portion it is necessary to remove.

Bending Glass Tubes. — If a sudden bend is wanted, heat only a small portion of the tube to a dull red-heat, and bend it with the hand held at the opposite ends. If the bend is to be gradual, heat an inch or two of it in length, previous to bending it. If a gradual bend on the one side, and a sharp one on the other, as in retorts, a little manage

oil, gold size, japan, and Brunswick ment of the tube in the flame, moving it | black. Dig out a foundation facing the to the right and left alternately at the

front door against the back wall for same time that it is turned round, will the boiling furnace, Fig. 2; against the easily form it of that shape. In bending

back wall, in the right-hand corner, dig glass, the part which is to be concave is

| out a foundation for the gum furnace, to be the part most heated. An ordinary

Figs. 3 and 4; this and all the other furgas flame is quite sufficient to bend glass by, but that of a spirit lamp is better.

FIG. 3. Glass, to Powder.- Make a piece of glass red hot in the fire, and while in This state plunge it into cold water; it will immediately break into powder; this must be sifted and dried; it is then fit for making glass paper, for filtering varnishes, and for other purposes.

Manufacture of Varnishes.The building in which varnish is made ought to be quite detached from any other building whatever, and have a door-way in the centre with folding daces require to have slow fires kept ia doors made to lift off the hinges. Let them for a day, in order to dry them the roof of the building slope to the slowly, and prevent their cracking. front; fix also in each end wall a frame Fig. 3, the top plate, is of cast iron. and door made to lift off the hinges, so Gum pot.- Procure a copper gum pot that, when necessary, there may be al to fit into the last furnace, Fig. 4. The free draught through the premises. Let bottom a, Fig, 4, is hammered out of a three skylights be made and fixed in the solid block of copper, and fashioned, all roof, not directly over the furnaces, but of one piece, exactly like a hat without on one side, so as to throw light on the the brim. The upper part of the pott, furnaces. The skylights and flaps must is made of sheet copper, of a cylindrical

| 76

« AnteriorContinuar »